Propellant charge with rearwardly attached tamping body for nonrecoiling weapons



1965 K. WENGENROTH ETAL 3,216,323

PROPELLANT CHARGE WITH REARWARDLY ATTACHED TAMPING BODY FOR NONRECOILINGWEAPONS Flled July 29, 1963 IA/VFNTOPS' A Or/ WZA/GE/VPOTI/ MV/IE/ITIPEP/W55 United States Patent G p 7 3,216,323 PROPELLANT CHARGE WITHREARWARDLY AT- TACHED TAMPING BQDY FOR NUNRECOILING WEAPONS KarlWengenroth, Munich, and Wilhelm Perniss, Numberg, Germany, assignors toDiehl, Nurnberg, Germany Filed July 29, 1963, Ser. No. 298,385 Claimspriority, appiieation Germany, Aug. 1, 1962, W 32,717; Aug. 11, 1962, D39,605; Dec. 20, 1962, 1) 40,556

11 Ciaims. (Cl. 891.7)

The present invention relates to improvements in nonrecoiling weaponsand relates more specifically to an improved arrangement of a tampingbody behind the propellant charge in such a weapon.

Armor piercing, mostly over-calibrated explosive missiles, may be firedby using firearms which, to avoid recoiling effects upon the weapon,utilize a tube having an opening at its rear end. A tamping body,filling the tube diameter tightly, is provided behind the propellantcharge for improving the force of the propellant charge on the missile.

In a known construction, this tamping body consists of stapled paperlayers which will blow out of the rear of the tube, supposedly, asrelatively harmless debris, when the projectile is fired. The usefuleffect of such a tamping body, however, is very low. Furthermore, thesepaper layers will gather together in lumps, so that, when using suchtamping in an effective amount, the area behind the rifleman will not beentirely free from danger.

The object of this invention is to provide the propellant charge of anonrecoiling weapon with a tamping body which will be effective butwhich will not be of danger within the area behind the rifleman.

The tamping body according to the invention, furthermore, improves theweapon, in such a way, that the initial velocity (V of projectiles firedfrom the weapon is kept substantially constant, thus improving theaccuracy of the weapon.

A further object of the invention is to increase the efficiency of theweapon by preventing the development of undue high gas pressure whichwould cause an un wanted increase of the recoil of the weapon tube.

A further object of the invention is to compensate for the influence oftemperature upon the propellant load and thus upon the initial velocityof the projectile.

The tamping body according to the invention includes in particular thefollowing characteristics:

(a) The tamping body according to the invention preferably consists ofdust or powder, in particular of metal dust or metal powder, pressed tothe form of a body with or without a cementing agent. One or more ofsuch pressed bodies may be used to make up a tamping body. Thecharacteristic of this tamping body is to be chosen so, that theinternal cohesive or adhesive structure thereof will be disruptedthrough the shock of the firing, so that it will be destroyed completelyas to form and become dust or powder again, and in this form leave theweapon tube, propelled by the gases of the propellant charge. Dust orpowder of pure or substantially pure iron of suitable grain size ispreferred.

(b) The tamping body, consisting of one or more pressed bodies, can becased in an air-tight and dampproofed enevelope, for example, a caseformed out of light inflammable or light meltable material, particularlyof plastic (polyethylene), to guarantee good transportation facilitiesand long life storage conditions.

(0) The weight of the tamping body is chosen as large as possiblecompared to the weight of the projectile. It should preferably be of topercentage of the weight of the projectile. The tamping body, with itsdiameter, however, does not fill the inner diameter of the barrel icecompletely but consists of one or more channels, arranged inlongitudinal direction of the weapon tube, through which channel orchannels a part of the propellant gas may escape rearwardly upon firing,before the tamping body has left the tube. The channel or channels arepreferably constructed so that the diameter of the tamping body is of asmaller diameter than that inner diameter of the tube.

(d) Furthermore, the tamping body can be provided with a packing, suchas a wraping, consisting of a selfsealing textile tape, in order toprovide that the aforementioned channel means for the propellant gas,provided between the weapon tube and the tamping body, is, after thefiring of the weapon maintained as long as possible, at least until thepressure of the gas has passed its maximum value and has come down to alower value.

(e) The casing of the tamping body can be combined for instance, bywelding with a casing containing the propellant charge which ispreferably of plastic (polyethylene) material. This connection, however,should be only so strong, that, upon firing of the weapon, the saidchannel means is available before the pressure in the tube reaches itsmaximum value. For this purpose one or both of the casings is providedwith a weakened spot.

(f) The tamping body can furthermore be provided with an arrangement tolower, or to compensate for the influence of temperature upon thepropellant charge and thus upon the initial or muzzle velocity V of theprojectile. This arrangement should, with increasing temperature enlargethe cross-section of the channel means and decrease it as thetemperature decreases. Such an arrangement could either be designed tobe adjustable manually or to be controlled automatically by theinfluence of the temperature. In a simple construction, the tamping bodyis provided with an adhesive tape which is wound around it and which maybe added to or subtracted from according to the ascertained temperaturebefore placing the tamping device into the weapon tube.

Further characteristics of the invention will become apparent from thefollowing description and examples taken together with the accompanyingdrawings wherein:

FIGURE 1 is a side view partly in section of a hand firearm ready tofire provided with an armor piercing projectile or missile, a propellantcharge, and a tamping body according to the invention;

FIGURE 2 is a fragmentary view like FIGURE 1, but showing the propellantcharge and the tamping body in section;

FIGURE 3 is an enlarged fragmentary view of the region inside circle aof FIGURE 2 showing the arranging of a bandage or wrapping around thecasing of the tamping body;

FIGURE 4 is a section view of a modification of the tamping body; and

FIGURE 5 is a perspective view of the FIGURE 4 modification.

The nonrecoiling weapon, illustrated in FIG. 1, consists in particularof a relatively thin walled tube 1, open on both ends, and provided witha firing device 2 mount ed in the bottom intermediate the ends. Theinside of the tube 1 communicates with the firing device 2 via adetonating or ignition canal or passage 3. The fusing cartridge 5 isexploded by operating the firing trigger 4, thereby causing an ignitionflash which blows into the inside of tube 1 via the ignition canal 3.The necessary sighting device provided on the tube 1 is not shown in thedrawing.

FIG. 1 also illustrates the position of tamping body 6 and propellantcharge body 7 within the weapon tube 1. The front end 7' of thepropellant charge body 7 projects into a recess in the rear end 9 of theprojectile. The projectile 10, has a reduced rear end 11 which isreceived in the tube 1, and which reduced rear end is provided withguiding ring means 12 and 13.

When loading the weapon, the projectile 1t propellant charge body 7, andtamping body 6, are stacked together, and are then inserted into theweapon tube from the front end. A so-called igniting or primer charge 8,provided within the propellant load body, is, it will be noted,positioned above the ignition canal 3.

FIG. 2 shows the construction of the propellant load with its combinedtamping body according to the invention. A cylindrical case 14 with awall-thickness of about 1.5 millimeters is made of plastic(polyethylene) and may be closed at its front end. The wall-thickness ofthe saidplastic case is reduced to about 0.5. millimeter within therange of the igniting charge 8 and at its rear end 15. Case 14 fitssnugly into tube 1.

The rear end part 15 of the propellant load case 14 is filled with apart of the propellant charge 16, which for instance, may consist of anitrocellulose powder of a suitable composition and grain size. Theigniting charge 8 is contained between two paper board disks 17. Theigniting charge 8 may be, for example, a black powder which will ignitethe main propellant charge 16 after the charge 8 has been ignited by theignition flash entering tube 1 via canal 3 and piercing casing 14. Thefront part of the propellant charge case 14 is also filled withnitrocellulose powder so that propellant charge 16 is in two parts withthe igniting charge 8 therebetween.

A cylindrical case 18 is provided on the tamping body 6 and is fitted tothe reduced diameter rear end 15 of the propellant charge case 14. Case18 is, for example, polyethylene material with a thickness of 0.15millimeter, and may be welded to the said rear end 15 of case 14 alongtwo ring-shaped annular regions 19, for instance by means of ring-shapedelectrically heated means. The actually tamping body 20 is positionedinside case 18. The right, or rear end, of case 18 is sealed from theair, by a bottom plate 21 which is Welded to the case 18. Furthermore,there are a few layers of self-sealing textile tape 22 wound around thecase 18, as shown in FIG. 3.

According to the invention, the tamping body may consist of iron dust,pressed with or Without a cementing agent, to a cylindrical block 20(FIG. 2) or to shorter blocks 20' (FIG. 4). The essential thing is thatthe structure of the tamping body, on the one hand, is sufficiently firmand solid that, it will keep its form under normal conditions, while, onthe other hand, it will loosen up and return to powdered or granularcondition under the firing thrust of the weapon. Thus, the tamping bodywhen leaving the rearwardly directed tube opening, will be carried asdust the shortest distance by the gases leaving the rear of the tube.

The tamping body may be produced for instance in the manner described inthe following:

Pure, substantially pure, iron with a medium size of grain, of adiameter, for example, of 0.06 millimeter, which may be produced by anelectrolytic method, is pressed under high pressure into a cylindricalblock of more or less length or into ring-shaped bodies. Adding alubricant to the iron dust helps to obtain uniform density in thepressed bodies, and also to protect the pressing devices. The lubricantmay, for instance, consist of 1 to 2 percentage of oil in the iron dust.Pressing can be accomplished by a pressure of about 1 to 2 tons/ cm. andwill result in bodies having a specific gravity ranging between 4 andgrams/cm. A body, pressed in this manner, is stable to handle but willdisintegrate into dust again under the impact of the firing thrust ofthe weapon. The bodies when stored, and protected by the case 8 againstthe humidity of the air, will keep their characteristics for a longperiod of time.

Instead of using iron dust, other dusts may also be used,

for instance, copper or lead dust, but these may be injurious to healthand iron dust is, therefore, preferred.

It is a further important object of the invention not to fill the tubediameter completely with the tamping body, but to leave an annularclearance 24 of a suitable size between the inside of tube 1 and theoutside of the tamping body. This clearance or channel means should bemaintained for a certain period of time after the firing of the weapon.As mentioned before, a part of the propellant charge gases will blow outof the tube to the rear through this said annular clearance in thismanner, by passing the tamping body. This clearance for instancemeasures 2.3 millimeters for a weapon having a caliber of 43.6millimeters.

This annular clearance is available immediately after the ignition ofthe propellant charge. It is a further important object of the inventionto provide, for this purpose, a breaking region at the connection of thepropellant charge case 14 to the case 18 of the tamping body as, forexample, at point 23, which represents a weakened region in case 14.This weakened region will rupture upon firing of the Weapon and bodywith its case, and the rear end 15 of the propellant charge case 14,will be moved towards the right by the firing operation, so that thepropellant charge gases can blow rearwardly through the annularclareance 24 immediately after the tearing off of the case 14 at thespot 23.

As it is beforementioned, the tamping body according to the inventionshould not only reduce the danger in the area behind the weapon duringfiring operation, but should also improve the operating properties ofthe weapon.

Using a pressed member in the tamping body with a specific gravity of 4to 5 grams/cm. will allow the use of a relative large tamping mass,through which the efliciency of the ammunition will be increasedremarkable. However, the disadvantage arises that, with the enlarging ofthe mass of the tamping body, the muzzle velocity V of the projectileand the maximum value of the pressure developed in tube 1 are alsoincreased. If the weapon is not to become too heavy, the pressure in thetube must exceed the range of 800 to 900 atmospheres. To achieve a lowpressure of the gas within the tube, it is necessary to enlarge thecombustion chamber to a relative large size. By using a larger tampingmass, the combustion chamber can be supplied with a small amount ofpropellant charge. This has, on the other hand, the disadvantage ofconsiderable variation in the muzzle velocity V of the projectile. Thisshows that the characteristics of the weapon may not be improved simplyby enlarging the tamping mass.

It is another important object of the present invention, to provide achannel in the longitudinal direction between the inside of the tube andthe tamping body through which said channel a part of the propellantcharge gas may blow off to the rear of the tube. Calculation andexperimentation have proved that such a blow off channel executes animportant influence upon the maximum pressure developed in the tube, andalso upon the projectile V so that, by providing a suitable dimensionedchannel, the maximum pressure developed in the tube may be decreased toa remarkably low value without decreasing thereby the projectile V Withsuch a said blow off channel, it will thus be possible to use a tampingmass of a very large volume, whereby a specified maximum of pressurewill not be exceeded. It is also possible to enlarge the propellantcharge by means of the determined combustion chamber. Through thismeasure, the variation of the initial velocity V of the projectile willbe decreased considerably without detraction from the efliciency,especially because the tamping body remains in the tube for a longerperiod of time, and through important differences in the manner thepropellant charge acts in the combustion chamber.

It is, however, essential that the blow off channel be maintained fromthe beginning of the pressure rise in the tube up to the point of timeat which the maximum of pressure is passed during the firing operation.It will also be obtained in this way, that the occurring projectile V isclose to the value calculated therefor. The proposed bandage orwrapping, surrounding the tamping body must be selected, thus, so thatthese requirements are met.

Calculations and experiments have proved that the reducing of the crosssection area of the tamping may vary over a relatively large range,within about 4 and 40 percent of the tube area. An optimum value isabout 6 to 7 percent of the cross sectional area of the tube.

In order to be able to operate the weapon within the range oftemperature from 20 to +40 centigrade, it is necessary to provide theweapon with a correction device combined with the sighting device, asbecause the influence of the temperature upon the propellant charge and,thus upon the V of the projectile must be compensated. According to afurther object of the invention, this influence of the temperature iscompensated in a relatively simple manner, simply by alternating thecross sectional area of the blow off channel.

A simple example is illustrated in the FIGS. 4 and for effecting such acompensation. The annular clearance 25 provided between the tamping body21) and the weapon tube 1 is of maximum value for the V of theprojectile at +40 centigrade. The tamping body has on its front part abandage or wrapping 26, wound around it, and consisting of aself-sealing textile tape, which reduces the cross sectional area of theannular clearance such that, if the whole of the bandage 26 remainswound upon the tamping body, the resulting clearance will give a certainV of, the projective, for a given propellant charge temperature ofcentigrade. Before loading, i.e., before placing the projectile into thetube, the rifleman rewinds the textile tape 26 to a determined mark andtears off the remainder according to the ascertained temperature. Thetape may be provided not for this purpose, with markings of temperatureand can be perforated as at 28 within certain separations so as to beeasily torn off.

The case of the tamping body is also provided with ribs or the like 27(FIG. 5) for centrally supporting the tamping body within the tube 1.

The invention is not restricted to the examples illustrated. Accordingto the illustrated examples, the blow off channel consists of an annularclearance between the tube and the tamping body. It is also possible toprovide one or several channels arranged around or within the tampingbody, for instance, whereby the tamping body or its bandage 22 can befitted closely within tube 1.

Some other solutions are possible for constructing the predescribedrated breaking point or spot within departing the scope of the presentinvention.

Also automatic acting devices, such as bimetal elements, may be providedin place of the predescribed packing or bandage 26, which, will enlargeupon an increase in temperature and reduce upon a reduction intemperature and thereby control the cross sectional area of the blow offchannel automatically. All of the elements in the tube, apart from theprojectile consist of inflammable or meltable material, in particular ofplastic or the like, convertible by the firing of the weapon into dustor fine granules.

What we claim is:

1. In a weapon having a .barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be expelled fromthe rear end of the barrel upon exploding of said charge, the adjacentends of said casing and tamping body having connecting means of lessdiameter than said barrel connecting said tamping body to said casing,said tamping body comp-rising body means of finely comminuted materialcompacted into solid members of a predetermined fixed configurationwhich can be handled without breaking but which will be ruptured so asto return to substantially the original particle size under the shock ofexplosion of said charge so as to leave the barrel in the originalparticle size, the maximum cross-sectional area of said tamping body andsaid connecting means being smaller than the cross sectional area of thebarrel to provide an escape channel means for gas past the tamping bodyat the time of exploding said charge.

2. In a weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be expelled fromthe rear end of the \barrel upon exploding of said charge, the adjacentends of said casing and tamping body having connecting means of lessdiameter than said barrel connecting said tamping body to said casing,said tamping body comprising body means of finely comminuted materialcompacted into solid members of a predetermined fixed configurationwhich can be handled without breaking but which will be ruptured so asto return to substantially the original particle size under the shock ofexplosion of said charge so as to leave the barrel in the originalparticle size, the maximum cross-sectional area of said tamping body andsaid connecting means being smaller than the cross sectional area of thebarrel to provide an escape channel means for gas past the tamping bodyat the time of exploding said charge, said comminuted materialcomprising iron dust or powder and said solid members having a specificweight of about 4 to 5 grams/cm.

3. In a weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be expelled fromthe rear end of the barrel upon exploding of said charge, the adjacentends of said casing and tamping body having connecting means of lessdiameter than said barrel connecting said tamping body to said casing,said tamping body comprising body means of finely comminuted materialcompacted into solid members of a predetermined fixed configurationwhich can be handled without breaking but which will be ruptured so asto return to substantially the original particle size under the shock ofexplosion of said charge so as to leave the barrel in the originalparticle size, the maximum crosssectional area of said tamping body andsaid connecting means being smaller than the cross sectional area of thebarrel to provide an escape channel means for gas past the tamping bodyat the time of exploding said charge, said comminuted materialcomprising iron dust or iron powder having an average particle diameterabout 0.06 millimeter, about 1 to 2% of weight by oil included in saidmaterial, and the specific weight of said solid mem bers being about 4to 5 grams/cm.

4. In a weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be expelled fromthe rear end of the barrel upon exploding of said charge, the adjacentends of said casing and tamping body having connecting means of lessdiameter than said barrel connecting said tamping body to said casing,said tamping body comprising body means of finely comminuted materialcompacted into solid members of a predetermined fixed configurationwhich can be handled without breaking but which will be ruptured so asto return to substantially the original particle size under the shock ofexplosion of said charge so as to leave the barrel in the originalparticle size, the maximum cross-sectional area of said tamping body andsaid connecting means being smaller than the cross sectional area of thebarrel to provide an escape channel means for gas past the tamping bodyat the time of exploding said charge, said tamping body including an airand liquid impervious enclosure or casing enclosing said solid members.

5. In a weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be expelled fromthe rear end of the barrel upon exploding of said charge, the adjacentends of said casing and tamping body having connecting means of lessdiameter than said barrel connecting said tamping body to said casing,said tamping body comprising body means of finely comminuted materialcompacted into solid members of a predetermined fixed configurationwhich can be handled without breaking but which will be ruptured so asto return to substantially the original particle size under the shock ofexplosion of said charge so as to leave the barrel in the originalparticle size, the maximum cross-sectional area of said tamping body andsaid connecting means being smaller than the cross sectional area of thebarrel to provide an escape channel means for gas past the tamping bodyat the time of exploding said charge, the said cross sectional area ofsaid tamping being of a size as to leave from 4 to 40% of the crosssectional area of the barrel unobstructed to form the said escapechannel means.

6. The arrangement according to claim 5 in which the maximum diameter ofthe tamping body is smaller than the inner diameter of the barrelwhereby said channel means comprises an annular channel Surrounding saidtamping body.

7. In a Weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be expelled fromthe rear end of the barrel upon exploding of said charge, the adjacentends of said casing and tamping body having connecting means of lessdiameter than said barrel connecting said tamping body to said casing,said tamping body comprising body means of finely comminuted materialcompacted into solid members of a predetermined fixed configurationwhich can be handled without breaking but which will be ruptured so asto return to substantially the original particle size under the shock ofexplosion of said charge so as to leave the barrel in the originalparticle size, the maximum cross-sectional area of said tamping body andsaid connecting means being smaller than the cross sectional area of thebarrel to provide an escape channel means for gas past the tamping bodyat the time of exploding said charge, said tamping body including an airand liquid impervious enclosure or casing enclosing said solid members,and wrapping means wrapped about said casing for controlling thediameter thereof and thereby controlling the size of the annularclearance between the tamping'body and the barrel forming said escapechannel means.

8. In a weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in thebarrel behind said projectile; a tamping body in the barrel behind thepropelling charge and adapted to be expelled from the rear end f thebarrel upon exploding of said charge, said tamping body comprising bodymeans of finely comminuted material compacted into solid members of apredetermined fixed configuration which can be handled without breakingbut which will be ruptured so as to return to substantially the originalparticle size under the shock of explosion of said charge so as to leavethe barrel in the original particle size, the maximum crosssectionalarea of said tamping body being smaller than the cross sectional area ofthe barrel to provide an escape channel means for gas past the tampingbody at the time of exploding said charge, said tamping body includingan air and liquid impervious enclosure or casing enclosing said solidmembers, a frangible casing surrounding said propelling charge and thecasing surrounding the propelling charge having an end portion of lesserdiameter connected to an end portion of the casing surrounding thetamping body to form a single unit, and a weakened zone provided in thecombined casings in the region of the interconnection thereof which willrupture under the force of said propelling charge when the latter isexploded.

9. The arrangement according to claim 8 which includes means forchanging the effective cross sectional area of said escape channel meansto compensate for the influence of temperature upon the propellingcharge.

10. The arrangement according to claim 9 in which said means forchanging the cross sectional area of said escape channel means comprisesan adhesive tape element wound about the tamping body and provided withtemperature designations for indicating the amount of tape to beassociated with the tamping body under any ascertained temperatureconditions.

11. In a Weapon having a barrel open at both ends and adapted to receivea projectile in the front end and an explosive propelling charge in afrangible casing in the barrel behind said projectile; a tamping body inthe barrel behind the propelling charge and adapted to be exelled fromthe rear end of the barrel upon exploding of said charge, said tampingbody comprising body means of finely comminuted material compacted intosolid members of a predetermined fixed configuration which can behandled without breaking but which will be ruptured so as to return tosubstantially the original particle size under the shock of explosion ofsaid charge so as to leave the barrel in the original particle size, themaximum cross-sectional area of said tamping body being smaller than thecross sectional area of the barrel to provide an escape channel meansfor gas past the tamping body at the time of exploding said charge, saidtamping body including an air and liquid impervious enclosure or casingenclosing said solid members, the adjacent ends of said frangible casingand the tamping body casing having connecting means of less diameterthan said barrel connecting said tamping body to said frangible casing,said casing including rib means projecting from the outer surfacesthereof operable for engaging the inside of said barrel to hold saidtamping body in a central position therein.

References Cited bythe Examiner UNITED STATES PATENTS 1,108,716 8/14Davis 89-1.7 1,108,717 8/14 Davis 891.7 1,311,021 '7/19 Spear et a1.891.7 1,940,657 12/33 Woodford 102-43 2,156,605 5/39 Prettyman 89-l.72,923,239 2/60 Andrew et al 102-22 X 2,953,990 9/60 Miller l02-433,128,670 4/64 Blacker 891.7

FOREIGN PATENTS 540,979 9/55 Belgium. 577,318 5/46 Great Britain.

OTHER REFERENCES German application No. 1,107,129, Blacker, pub. May 18,1961, Class 72c 891.7.

BENJAMIN A. BORCHELT, Primary Examiner,

SAMUEL W. ENGLE, Examiner,

1. IN A WEAPON HAVING A BARREL OPEN AT BOTH ENDS AND ADAPTED TO RECEIVEA PROJECTILE IN THE FRONT END AND AN EXPLOSIVE PROPELLING CHARGE IN AFRANGIBLE CASING IN THE BARREL BEHIND SAID PROJECTILE; A TAMPING BODY INTHE BARREL BEHIND THE PROPELLING CHARGE AND ADAPTED TO BE EXPELLED FROMTHE REAR END OF THE BARREL UPON EXPLODING OF SAID CHARGE, THE ADJACENTENDS OF SAID CASING AND TAMPING BODY HAVING CONNECTING MEANS OF LESSERDIAMETER THAN SAID BARREL CONNECTING SAID TAMPING BODY TO SAID CASING,SAID TAMPING BODY COMPRISING BODY MEANS OF FINELY COMMINUTED MATERIALCOMPACTED INTO SOLID MEMBERS OF A PREDETERMINED FIXED CONFIGURATIONWHICH CAN BE HANDLED WITHOUT BREAKING BUT WHICH WILL BE RUPTURED SO ASTO RETURN TO SUBSTANTIALLY THE ORIGINAL PARTICLE SIZE UNDER THE SHOCK OFEXPLOSION OF SAID CHARGE SO AS TO LEAVE THE BARREL IN THE ORIGINALPARTICLE SIZE, THE MAXIMUM CROSS-SECTIONAL AREA OF SAID TAMPING BODY ANDSAID CONNECTING MEANS BEING SMALLER THAN THE CROSS SECTIONAL AREA OF THEBARREL TO PROVIDE AN ESCAPE CHANNEL MEANS FOR GAS PAST THE TAMPING BODYAT THE TIME OF EXPLODING SAID CHARGE.